Neuron Anaotomy 4 Flashcards
What are menings and what are the layers called
- protective covering
3 layers:
1- dura mater
2- arachnoid
3- Pia mater (adhered closely to brain surface)
- in between brain and scalp
Features of Dura mater
- Outer-most layer of meninges
- Dense and fibrous - tough
- Two layers - outer and inner
- Space between the layers forms venous sinuses - only between some places
- Inner layer forms dural folds
What are DURAL FOLDS formed from
- Formed from inner layer of dura mater
Three types of dural folds
- Falx cerebri
- separates cerebral hemispheres - median plane - Falx cerebelli
- separates cerebellar hemispheres - median plane - Tentorium cerebelli
- separates the cerebrum from the cerebellum - horizontal plane
Falx means (sickle-shaped) ‘
Lactation of venous sinus
Located where the two layers of dura mater separate
features of Arachnoid
- Layer beneath the dura mater
- Layer above the pia mater
- Does not extend into sulci (‘valleys’)
- Contains 2 special features:
- Subarachnoid space
- Arachnoid granulations - Contains blood vessels (within the subarachnoid space, lying on top of pia mater)
Arachnoid = Layer under dura + space under that
Subarachnoid space
- between arachnoid and the Pia matter
- filled with cerebrospinal fluid - helps with cousining (and contains blood vessels)
Arachnoid granulations
- perforate the inner layer of dura mater
- transport ‘old’ CSF from subarachnoid space into venous sinus
- the things that poke into venous sinus
Pia mater features
- Inner layer of the meninges - sit close to brain
- Transparent and delicate - still provides support to keep areas separated from one another and cushioning
- Blood vessels in arachnoid sit on top of pia mater
- Adheres to brain and follows gyri and extends into sulci
- only layer of the manengies that goes down into the indentations on surface of brain
How can u tell which side of the spinal cord u looking at
- Dorsal root ganglion
- Spinous process of vertebra
Are the meninges on the spinal cord too?
Yes - same order as brain - same layers present
The meningal sac is full of Serbral fluid - it is a massive subarachnoid space ????
The ventricular system features
- Network of interconnected “spaces” (= ventricles) within the brain
- Filled with cerebrospinal fluid (CSF), which nourishes and protects the brain
- Spaces lined with ependymal cells, which circulate the CSF (waving cilia)
- CSF is produced by the choroid plexus in
Ventricles
LABEL ON DIAGRAM!!!
Lateral ventricles (2)
- two of them
- one in each hemisphere
Third ventricle
- lactated in the diencephalon
Cerebral aqueduct
- connects 3rd ventricle to the 4th ventricle
- located in the midbrain
Fourth ventricle
- located at the level of the cerebellum
Central canal (spinal cord)
Four features of cerebrospinal fluid (CSF) and its circulation
- Produced by choroid plexus within ventricles
- Surrounds CNS, within subarachnoid space
- Provides support and cushion
- Transports nutrients and waste
Cerebrospinal fluid circulation path
Start: Lateral vertices
- 3rd ventricle
- cerebral aqueduct
- 4th ventricle - 4 holes it can come out of
- subarachnoid space
- within subarachnoid space it flows around brain and spinal cord
Exit: though arachnoid granulations into venous sinus
Lateral view of ventricles
